01 - Place chicken breasts between plastic wrap sheets and pound to 1/2-inch thickness using a meat mallet for even cooking.
02 - Whisk buttermilk and hot sauce in a large bowl. Add chicken, coat thoroughly, cover, and refrigerate for 1 hour up to overnight for maximum tenderness.
03 - Combine flour, cornstarch, paprika, garlic powder, onion powder, salt, black pepper, cayenne pepper, and thyme in a shallow dish. Mix well to distribute spices evenly.
04 - Whisk eggs and milk in a separate bowl until fully blended and smooth.
05 - Remove chicken from buttermilk, allowing excess to drip off. Dredge in seasoned flour, dip in egg wash, then dredge again in flour, pressing lightly to ensure coating adheres properly.
06 - Pour vegetable oil into deep skillet or Dutch oven and heat to 350°F for optimal frying conditions.
07 - Fry chicken in batches without overcrowding, cooking 5-7 minutes per side until golden brown and internal temperature reaches 165°F.
08 - Transfer fried chicken to wire rack or paper towels to drain excess oil. Let rest for 5 minutes before serving to maintain crispiness.